The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: rob650 on May 09, 2015, 02:45:56 PM

Title: valve adjustment problems issues at pushrod screw
Post by: rob650 on May 09, 2015, 02:45:56 PM
1982 R65.  Recently had my heads rebuilt and installing them back on today.

on the right hand side head, i am trying to adjust the valve clearances to .0045 intake and .0085 exhaust.  im using the adjustment screw at the top of the pushrod to create the gap, but am running out of thread with the screw before it bottoms into the rocker arm.  im having to put a lot more torque on those screws than i feel is necessary and im still not quite at the gap numbers.  the pushrods spin freely.  the heads are torqued down.  I dont know what else to consider.

FYI did the left hand side valve adjustments, no issues.

Thanks.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: Bob_Roller on May 09, 2015, 05:34:07 PM
Did you rotate the engine, until the right piston is at the top of it's travel ???
Title: Re: valve adjustment problems issues at pushrod screw
Post by: montmil on May 09, 2015, 06:39:24 PM
What Bob Roller said. [smiley=thumbup.gif]

Don't wish to insult your skill set but you must rotate the engine after the first cylinder's valve lash adjustment and bring the second cylinder to TDC, top dead center.

One thing comes to mind as a forum member recently had her R65's head's valve cut and the "tech" cut them so deeply that there was a lash adjustment problem where the adj screw couldn't be backed out far enough. Your issue appears to be the opposite so I'm in agreement with Bob R. Rotate 360 and confirm the piston is at TDC by peeking in the timing window.

Also, be sure the pushrod's ball end is fully seated in the lifter "pocket". Let us know how it goes.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: rob650 on May 09, 2015, 11:54:08 PM
NO not insulted one tick, im here for the cold hard truth and being called on my possible f*ck ups... yes the right cylinder was brought up to TDC after doing the left.

Pushrods appear to be seated fully in their pocket
Title: Re: valve adjustment problems issues at pushrod screw
Post by: Tony Smith on May 10, 2015, 12:32:58 AM
Do you have photos of the combustion chamber side of the heads?

If the push-rods are seated correctly and the rocker shafts correctly installed (and it looks to me like they are) then the only thing that can be wrong is that new valves were installed and they were too long, or the valves are the right size and they have been pocketed by the technician.

if the first then that at least can be fixed, the second is unforgivable.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: montmil on May 10, 2015, 08:51:37 AM
Quote

If the push-rods are seated correctly and the rocker shafts correctly installed (and it looks to me like they are) then the only thing that can be wrong is that new valves were installed and they were too long, or the valves are the right size and they have been pocketed by the technician.

if the first then that at least can be fixed, the second is unforgivable.

Shades of Ms DeeG's R65 valve work come back to haunt another?
Title: Re: valve adjustment problems issues at pushrod screw
Post by: rob650 on May 10, 2015, 04:03:39 PM
the first option is out, valves were not replaced.  pic attached post-valve job if that helps anyone.

So....gotta get a new head?
Title: Re: valve adjustment problems issues at pushrod screw
Post by: Tony Smith on May 10, 2015, 05:20:47 PM
Nice exhaust thread repair there.

The valves look Ok to me, i.e. not pocketed so the reason for your lack of valve lash clearance starts to venture into the realm of vaguely possible to absurd.


Do you have any other boxer engines hanging around that you might have accidentally exchanges push rods with?
 
How long was your engine apart? If it was a while i wonder f you have a little corrosion in the lifer bores preventing the cam followers from going fully home (you should be able to move them freely with one of those extending magnet pickup tools and you will quickly know if full travel is available as they should "clonk" nicely when they hit the cam.
 
You have the pre-1985 heads so there are no spacers aside from the pressed in "button" to go between the rocker shaft pillows and the head. i admit that this has me perplexed, too much clearance is usually a simply assembly error, too little clearance is bordering on wierd.

Title: Re: valve adjustment problems issues at pushrod screw
Post by: Tony Smith on May 10, 2015, 05:22:21 PM
Quote
Shades of Ms DeeG's R65 valve work come back to haunt another?


I remain incredulous that any machinist worthy of the name would have given cylinder heads back in the condition of those, that was sheer butchery.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: rob650 on May 10, 2015, 05:48:33 PM
Tony,

Exhaust thread repair done at San Jose Bmw a million years ago.

Just the one airhead.  Bike was apart for about 9 months, but covered/protected to avoid dirt and corrosion.  got the nice clonk when re-inserting the pushrods.

"lifter bores" -- these things in pic circled in yellow?  How do i get to them to inspect them?



 

Title: Re: valve adjustment problems issues at pushrod screw
Post by: Tony Smith on May 10, 2015, 06:31:19 PM
You can't really with the engine assembled, hence my suggestion that you pull the push-rods out and use a pickup magnet to move the lifters in their bores, you will quickly know if there is a problem because they should be almost totally free of resistance.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: Julio A. on May 10, 2015, 10:47:14 PM
Quote
Tony,

"lifter bores" -- these things in pic circled in yellow?  How do i get to them to inspect them?

 

A long screwdriver or a telescopic magnet should be enough to make them slide right out.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: Kookaburra on September 06, 2015, 01:06:49 AM
Not quite sure of your particular rocker design and this may be unhelpful but - are the rocker posts at the right height (ie seated correctly and with correct base washers/spacers) from the cylinder head seats?
Title: Re: valve adjustment problems issues at pushrod screw
Post by: Tony Smith on September 11, 2015, 11:47:59 PM
Just curious, was there ever an outcome on this? I would love to know the reason for the lack of adjustment - one thing that did occur was that if the needle rollers in the rocker ran away and hid that would do it. But you would notice that.
Title: Re: valve adjustment problems issues at pushrod screw
Post by: nhmaf on September 12, 2015, 10:13:36 AM
I wondered too - seems like either some washers/spacers might be missing from the rocker block assembly, or the headgasket was missing, or something?